1. Field of the Invention
The present invention generally relates to a tip over detection device for a motor vehicle. More particularly, the present invention relates to a tip over detection device using an accelerometer to detect when a motor vehicle excessively leans or lays down.
2. Description of the Related Art
Motorcycles generally comprise a frame with a steerable front wheel and a driven rear wheel. An engine is mounted within the frame between the front wheel and the rear wheel. The engine generally comprises at least one piston that reciprocates within a bore formed in the cylinder block. A cylinder head, together with the cylinder bore and the piston, defines a combustion chamber in which an air-fuel mixture is compressed and ignited. A throttle valve may be provided to control the air flow rate into the combustion chamber and a fuel injection system may be provided to control the amount of fuel mixed with the air. An ignition system, including a spark plug, ignites the air-fuel mixture that is compressed within the combustion chamber by the piston. Ignition and burning of the air-fuel mixture drives the piston downward within the cylinder bore. A connecting rod transfers the reciprocating linear movement of the piston to a rotatable crankshaft.
A controller, such as an electronic control unit (“ECU”), communicates with various engine and motorcycle components. The ECU, in particular, generally controls timing of the ignition system and injection of the fuel injection system based upon data received from various sensors. For instance, in some motorcycles, the ECU receives information regarding the engine speed from an engine speed sensor, the throttle position from a throttle position sensor and engine temperature from a temperature sensor. Based upon this information, various control maps (that are stored in memory) are consulted to determine a desired ignition timing and a desired injection amount and timing.
In some arrangements, the engine is not an internal combustion engine. Rather, due to recent governmental regulations, electric vehicles are becoming more popular. The electric vehicles generally employ an ECU to help control output of at least one electric motor based, at least in part, upon operator demand. Nevertheless, an ECU is used to at least partially control motor operation.
Motorcycles generally require operation at a lean angle relative to vertical; the lean angle is used to assist in turning. Motorcycles occasionally tip over (e.g., are leaned too far) during operation. When a motorcycle is laid on its side when running (either because of leaning too far or because of “high siding”), fuel can spill from the fuel supply system and the laid-down orientation of the motorcycle can otherwise adversely affect engine operation. Accordingly, a system is desired that will deactivate the fuel supply system and possibly the engine during such tipping. Additionally, motorcycles can tip over if the lean angle exceeds a certain angle at which the center of gravity is out of a controllable range. Under this condition, the system also is desired to deactivate the fuel supply.
The systems described above thus need an excellent tip over detecting device that can detect if the associated motorcycle excessively leans or tips over. Conventionally, mechanical tip over detecting devices are available. However, such mechanical devices are insufficient in accuracy of detection and in reliability. Improvements of the mechanical devices need complicated manufacturing processes and increase cost thereof. Furthermore, the mechanical devices are bulky and heavy such that a relatively large space and strong brackets are required. The strong brackets also waste a certain space.